Surgeons and medical professionals and personnel (e.g., doctors, veterinarians, dentist, nurses) use a plurality of instruments in performing surgery/treatment such as scalpels, forceps, sharps, scissors, clamps, needles, etc. The various instruments each have a specific function during surgery/treatment. Rigid trays are commonly used in order to support the plurality of instruments during surgery/treatment. The trays are typically kept horizontal by a stand or other structure so as to be relatively close to the surgical/treatment site. Medical personnel is often required to select and hand the instruments to the surgeon from the tray. Oftentimes, a nurse or the like is dedicated to selecting and handing instruments as requested by the surgeon.
It also has been common for medical personnel to place instruments directly on the patient surface for easy access to the instruments, and to create a transfer zone close to the treatment site. Such hands-free practice reduces the risk of percutaneous injury to medical personnel as well as the possibility of dropping the instruments as a result of being passed back and forth. However, as the patient usually represents an uneven surface, instruments may not be retained properly on the patient due to the effect of gravity and may roll or slide off the patient onto the floor.
A magnetic mat, magnetic drape or surgical drape (reusable in that it can be sterilized or single use) has been used into surgical rooms for a number of years as an alternative, in supplement or in combination to rigid trays for holding instruments or placing the instruments on the patient surface. One example thereof is the MagnaDrape™. The MagnaDrape™ consists of a flexible instrument-holding drape made of silicone, typically 12 inches by 16 inches, within which a plurality of permanent magnet units are positioned. The magnet units of the MagnaDrape™ are embedded or sandwiched in the drape. The flexible nature of the drape allows it to be laid onto uneven surfaces such as the body of the patient, in close proximity to the surgical or treatment site. The permanent magnet units of the MagnaDrape™ produce a magnetic field that will attract the surgical instruments and retain them on the drape even if the drape is not horizontal. As the permanent magnets are raised, there is defined free space between the permanent magnet units to facilitate the grasping of instruments. As they are typically made of ferromagnetic material, the surgical instruments do not have to be treated prior to being used with the MagnaDrape™ other than to be sterilized. Accordingly, with the MagnaDrape™, the surgical instruments may be retained in close proximity to or on a patient without the need for a support structure such as a stand.
However, the presence of permanent magnet units produces magnetic fields. The magnetic fields may have an effect on nearby electronic devices, implanted devices, or on the patient. For instance, a magnetic field of a given magnitude may alter the operation of implanted electronic devices used for stabilizing and/or controlling physiological parameters such as pacemakers, defibrillators, insulin pumps or regulators, pain control devices, any programmable medical devices or electronic devices, etc. Such magnetic fields can also affect the blood flow of the patient. In some instances, it is desired to reduce or avoid such side effect.